1. Field of the Invention
This invention is in the field of protective circuits for disabling system operation upon a malfunction, and in particular, to disable a movie projector substantially immediately upon cessation of film movement.
2. Description of the Prior Art
Devices have been proposed to stop the mechanical and/or electrical components of a film project upon film movement failure in order to prevent further damage to the film and to locate accurately the cause of failure. However, such devices are unreliable and involve substantial time lag between the time of failure and the time the electrical and mechanical components are disabled, causing possible film damage and making the failure cause difficult to detect.